Countable nouns (also called count nouns) are nouns that can be counted (e.g. oranges). Uncountable nouns (also known as non-count or mass nouns) are amounts of something which we cannot count (e.g. sand). So how do we know whether or not a noun is countable or uncountable?

The noun is countable:

• if we can use the indefinite artice a/an before it. Example: I own a car. / I play with an ostrich.
• if we can use the word 'many' (and not 'much') to describe it. Example: She has many friends. (It's wrong to say: She has much friends.)
• if we can express its quantity by using a number before it. Example: I have five apples.
• if it takes on singular as well as plural forms. Example: an orange / some oranges / fifty oranges

The noun is uncountable:

• if a/an is not normally used in front of it. Example: He is eating some rice. (NOT: He is eating a rice.) Rice is treated as not countable, so some (which can be used for both countable and uncountable nouns) is used with it.
• if the word much can be correctly used with it. Example: How much rice have you eaten? (NOT: How many rice have you eaten?)
• if it is not possible for us to count it. However, we can make it countable by having a quantity for it. Example: I have just bought two cartons or litres/liters of milk. (NOT: I have just bought two milk.)
• if it takes only a singular form. Example: some ice (NOT: some ices) / some ink (NOT: some inks) / some soup (NOT: some soups)

Countable and Uncountable Nouns are used with the following:

(See List 2 for uncountable nouns that can be made countable)